City got sweet revenge when they beat their title rivals at Athlone Stadium on Tuesday night after Sundowns beat them 3-2 at Loftus Stadium.
McCarthy paired up young Zwekeli Kewetu and Thato Mokeke in the centre of the park.
Erasmus got injured midway through the second half, which forced McCarthy to rethink his tactics.
“I was gonna throw him on but then Kermit got injured,” McCarthy explained to reporters.
“So Kermit actually killed it because if Shaka [Siphelele Mthembu] was on then Travis would’ve come in and [Surprise] Ralani would’ve probably or Zuki would have shifted to the left of the midfield and Travis and Thato [in the middle], you know.
“But unfortunately that change of bringing Travis on and taking Kermit off, we [would have] become too defensive. With Craigy [Craig Martin] if anything [is played] in behind they know they're up against a cheetah so ja!
“That was the aim, we wanted to also stretch them. So the ultimate goal was for Travis to come in and every time give him 15 till 20 minutes every time until I think yeah [he's ready to start].
“So now this little break is a good time to really work him a bit more and I think for Polokwane City he might be... maybe I can give him the nod.”